U.S. patent number 4,666,951 [Application Number 06/590,874] was granted by the patent office on 1987-05-19 for photo-curable epoxy resin composition.
This patent grant is currently assigned to Tokyo Shibaura Denki Kabushiki Kaisha. Invention is credited to Shuzi Havase, Yasunobu Onishi, Shuichi Suzuki, Moriyasu Wada.
United States Patent |
4,666,951 |
Onishi , et al. |
May 19, 1987 |
Photo-curable epoxy resin composition
Abstract
There is disclosed a photo-curable epoxy resin type composition
comprising an epoxy resin, an aluminum compound, a silicon compound
having a peroxysilyl group and a photosensitizer. The compositions
of the present invention can suitably be used for wide varieties of
electrical applications.
Inventors: |
Onishi; Yasunobu (Yokohama,
JP), Havase; Shuzi (Kawasaki, JP), Suzuki;
Shuichi (Yokohama, JP), Wada; Moriyasu (Ninomiya,
JP) |
Assignee: |
Tokyo Shibaura Denki Kabushiki
Kaisha (Kawasaki, JP)
|
Family
ID: |
12769371 |
Appl.
No.: |
06/590,874 |
Filed: |
March 19, 1984 |
Foreign Application Priority Data
|
|
|
|
|
Mar 23, 1983 [JP] |
|
|
58-47229 |
|
Current U.S.
Class: |
522/8; 522/13;
522/169; 522/170; 522/23; 522/24 |
Current CPC
Class: |
C08G
59/68 (20130101); G03F 7/0755 (20130101); G03F
7/0045 (20130101); G03F 7/038 (20130101) |
Current International
Class: |
C08G
59/68 (20060101); C08G 59/00 (20060101); G03F
7/075 (20060101); C08F 002/50 (); C08F 004/12 ();
C08F 004/18 (); C08F 004/34 () |
Field of
Search: |
;204/159.24
;522/13,24,8 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Other References
Roffey "Photopolymerization--" 1982, John Wiley & Sons, pp. 67,
68, 78, 102, 110. .
Dannley et al. "The Decomposition of Silyl Hydroperoxides" vol. 30,
pp. 3848-3851, (J. Org. Chem.). .
Crivello et al. "Photoinitiated Cationic Polymerization by
Dialkylphenacylsulfonium Salts", vol. 17, pp. 2877-2892; (Journal
of Polymer Science)..
|
Primary Examiner: Bleutge; John C.
Assistant Examiner: Koeckert; Arthur H.
Attorney, Agent or Firm: Schwartz, Jeffery, Schwaab, Mack,
Blumenthal & Evans
Claims
We claim:
1. A photo-curable epoxy resin composition which consists
essentially of:
(a) an epoxy resin,
(b) an organic aluminum compound,
(c) a silicon compound having a peroxysilyl group, and
(d) a photosensitizer which is other than said compounds (b) and
(c), said photosensitizer being capable of photosensitizing said
compound (c), such that said composition, when cured, contains no
ionic impurities, said photosensitizer being at least one selected
from the group consisting of an aromatic hydrocarbon, a
benzophenone, an acetophenone, a benzoin, a benzoin ether, a
xanthone, a thioxanthone, a disulfide, a quinone, a halogenated
hydrocarbon, benzil and an amine.
2. A photo-curable epoxy resin composition according to claim 1,
wherein said compound (a) consists essentially of an epoxy compound
alone or a combination of an epoxy compound with at least one
compound selected from the group consisting of an acid anhydride, a
phenol series compound, an ethylenic compound and an imide
compound.
3. A photo-curable epoxy resin composition according to claim 2,
wherein said ethylenic compound is at least one compound selected
from the group consisting of a styrene and derivatives thereof; an
unsaturated carboxylic acid, an unsaturated carboxylate; an ester
of an unsaturated carboxylic acid with an aliphatic hydroxyl
compound, an aliphatic polyhydroxy compound, an aromatic hydroxyl
compound or an aromatic polyhydroxy compound; a polycarboxylic acid
containing two or more carboxyl groups; and an oligoester obtained
by esterifiction reaction of a polyhydroxyl compound containing two
or more hydroxyl groups and an unsaturated carboxylic acid.
4. A photo-curable epoxy resin composition according to claim 1,
wherein said organic aluminum compound has an organic group
selected from the group consisting of an alkoxy group, a phenoxy
group, an acyloxy group, a .beta.-diketonato group and an
o-carbonylphenolato group.
5. A photo-curable epoxy resin composition according to claim 1,
wherein said silicon compound having a peroxysilyl group has the
following general formula:
wherein R.sup.1 represents a hydrogen atom, a halogen atom, an
alkyl group having from 1 to 5 carbon atoms, a vinyl group, an
alkoxy group having from 1 to 5 carbon atoms or a substituted or
unsubstituted aryl group; R.sup.2 represents a hydrogen atom, an
alkyl group having from 1 to 10 carbon atoms or a substituted or
unsubstituted aryl group; and n is an integer of 0 to 3.
6. A photo-curable epoxy resin composition according to claim 1,
wherein said aluminum compound and silicon compound having a
peroxysilyl group are used in amounts of 0.001 to 10% by weight and
0.01 to 20% by weight based on the epoxy resin, respectively.
7. A photo-curable epoxy resin composition according to claim 6,
wherein said photosensitizer is used in an amount of 0.01 to 20% by
weight based on the epoxy resin.
8. A photo-curable epoxy resin composition according to claim 1,
wherein said silicon compound having a peroxysilyl group is
substituted by two or three aryl groups directly linked to a
silicon atom.
9. A photo-curable epoxy resin composition according to claim 1,
wherein said photosensitizer is selected from the group consisting
of benzophenone, benzoin ethyl ether, benzoin isopropyl ether,
thioxanthone, 2,4-dimethylthioxanthone and naphthalene.
Description
BACKGROUND OF THE INVENTION
This invention relates to a photo-curable epoxy resin composition,
and more particulaly to a photo-curable epoxy resin composition
which has been improved in curing characteristics and which
provides a cured product having suitable electric characteristics
for use as insulating and resist material in electric
equipment.
Recently, a process for hardening a resin by the use of a light is
attracted attention to save energy and improve operating efficiency
in the field of resins. Among others, processes for photo-curable
the epoxy resins are regarded as important because of wide range of
their possible applications. In a process for photo-curing an epoxy
resin, the epoxy resin itself is very important, besides the curing
conditions. Thus, compositions having various formulations have
widely been studied. The photo-curable epoxy resin compositions,
which have hitherto been known to the art, can roughly be
classified into two groups.
One is an epoxy resin which has been modified by using a
photo-polymerizable compound containing a vinyl group or vinyl
groups, such as acrylic acid and its derivatives. However,
photo-cured products obtained from the modified epoxy type resins
have the defects that heat resistance is considerably inferior to
that of photo-cured products obtained from epoxy resins
themselves.
The other is an epoxy resin which is added a photo-decomposable
catalyst and is to be cured by the catalyst. As the
photo-decomposable catalyst used for the purpose, there may be
mentioned the complex having the following formula: ##STR1##
wherein Ar represents a phenyl group; X represents an iodine atom,
a sulfur atom or a diazo group; and Y represents BF.sub.4,
PF.sub.6, AsF.sub.6 or SbF.sub.6.
[See, for example, Macromolecules, Vol. 10, 1307 (1977); Journal of
Radiation Curing, Vol. 5, 2 (1978); Journal of Polymer Science,
Polymer Chemistry Edition, Vol. 17, 2877 (1979); Ibid. Vol. 17,
1047 (1979); Journal of Polymer Science, Polymer Letters Edition,
Vol. 17, 759 (1979); Japanese Provisional Patent Publication No.
65219/1980; U.S. Pat. No. 4,069,054; and British Pat. Nos.
1,516,511 and 1,518,141.]
In case of the epoxy resin compositions which are added the
photo-decomposable catalysts, obtained photo-cured products show
good mechanical and thermal characteristics. In this case, however,
the catalyst components remain as ionic impurities in the
photo-cured products so that when such photo-cured products
containing the ionic impurities are used in electric equipment, it
has the problems that the ionic impurities adversely affect the
electric characteristics of the photo-cured products such as an
electric insulation ability and sometimes cause an electric
equipment or the like to corrode.
It is an object of this invention to provide a photo-curable epoxy
resin type composition which may eliminate the above-mentioned
disadvantages and has good storability under room temperature and
cool-and-dark place, quickly hardens with irradiation of light,
particularly of ulraviolet rays, and can be heat-cured at a
temperature of not less than 150.degree. C., and gives a cured
product containing no ionic impurities, causing no corrosion of a
metallic material which is contacted with the cured product and
having excellent electrical characteristics.
SUMMARY OF THE INVENTION
As a result of inventive studies made by the present inventors, it
was found that the above object can be achieved by using as
photo-curing catalysts an aluminum compound and a silicon compound
having a peroxysilyl group, in combination with the epoxy resin,
and by using further a photosensitizer. The invention has thus
accomplished.
Namely, the photo-curable epoxy resin type composition according to
this invention comprises:
(a) an epoxy resin,
(b) an aluminum compound,
(c) a silicon compound having a peroxysilyl group, and
(d) a photosensitizer.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The composition according to this invention will be described more
detail in the following.
The epoxy resin which may be used in accordance with the present
invention contains an epoxy compound alone or a combination of an
epoxy compound with one or more compounds selected from the group
consisting of an acid anhydride, a phenol series compound, an
ethylenic compound and an imide compound.
The epoxy compound to be used in this invention constitutes a
principal component of the composition of this invention. As the
epoxy compound, they may be mentioned, for example, a
mono-functional epoxy compound and a polyfunctional epoxy compound.
Examples of the mono-functional epoxy compounds may include an
ethylene oxide, a propylene oxide, a butylene oxide, a styrene
oxide, a phenyl glycidyl ether, a butyl glycidyl ether and the
like. Examples of the poly-functional epoxy compounds may include a
bisphenol A type epoxy resin; a bisphenol F type epoxy resin; a
phenol-novolac type epoxy resin; an alicyclic epoxy resin; a
heterocyclic ring-containing epoxy resin such as triglycidyl
isocyanaurate, hydantoin epoxy, or the like; a hydrogenated
bisphenol A type epoxy resin; an aliphatic epoxy resin such as
propylene glycol diglycidyl ether, pentaerythritol polyglycidyl
ether or the like; a glycidyl ester type epoxy resin obtained by
the reaction of an aromatic, aliphatic or alicyclic carboxylic acid
with epichlorohydrin; a spiro ring-containing epoxy resin; a
glycidyl ether type epoxy resin which is a reaction product of an
o-allyl-phenol-novolac compound and epichlorohydrin; a glycidyl
ether type epoxy resin which is a reaction product of a diallyl
bisphenol compound, having an allyl group at the o-position of each
of the hydroxyl groups in bisphenol A, and epichlorohydrin; etc.
One or more kinds selected from the group consisting of the above
may be used optionally.
As the phenol series compound to be used by being added to the
epoxy compound, there may be mentioned bisphenol series compounds
such as bisphenol A, bisphenol F, bisphenol S and the like; and a
condensate of phenols such as phenol, cresol, catechol, bisphenol A
and the like with formaldehyde; etc.
As the ethylenic compound to be used in this invention, there may
be mentioned styrene and derivatives thereof; unsaturated
carboxylic acids, unsaturated carboxylates; esters of unsaturated
carboxylic acids with aliphatic hydroxyl compounds, aliphatic
polyhydroxy compounds, aromatic hydroxyl compounds or aromatic
polyhydroxy compounds; polycarboxylic acids containing two or more
carboxyl groups; oligoesters obtained by esterification reaction of
polyhydroxyl compound containing two or more hydroxyl groups and
unsaturated carboxylic acids; etc.
Examples of the unsaturated carboxylic acids may include acrylic
acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic
acid, maleic acid, etc.
Examples of the aliphatic hydroxyl compounds may include methanol,
ethanol, propanol, butanol, etc.
Examples of the aliphatic polyhydroxyl compounds may include
dihydric alcohols such as ethylene glycol, triethylene glycol,
tetraethylene glycol, tetramethylene glycol, neopentyl glycol,
1,10-decandiol, 1,2-butanediol, 1,3-butanediol and propylene
glycol; trihydric alcohol such as trimethylolethane and
tetramethylolethane, and a polymer thereof; alcohols containing
four or more hydroxyl groups such as pentaerithritol,
dipentaerithritol, tripentaerithritol and other polymeric
pentaerithritol, saccharides such as sorbitol and D-mannitol;
dihydroxycarboxylic acids such as dihydroxymaleic acid, etc.
Examples of the aromatic hydroxyl compounds and the aromatic
polyhydroxyl compounds may include phenol, hydroquinone, catechol,
resorcinol, phloroglucinol, pyrogallol, etc.
Examples of the esters of aliphatic hydroxyl compounds with
unsaturated carboxylic acids may include acrylic esters such as
methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl
acrylate, n-butyl acrylate and tert-butyl acrylate; methacrylic
esters such as methyl methacrylate, ethyl methacrylate, n-propyl
methacrylate, isopropyl methacrylate, n-butyl methacrylate and
tert-butyl methacrylate; itaconic esters such as methyl itaconate,
ethyl itaconate, n-propyl itaconate, isopropyl itaconate, n-butyl
itaconate and tert-butyl itaconate; crotonic esters such as methyl
crotonate, ethyl crotonate, n-propyl crotonate, iso-propyl
crotonate, n-butyl crotonate and tert-butyl crotonate; etc.
Examples of the esters of aliphatic polyhydroxyl compound and
unsaturated carboxylic acid may include acrylic esters such as
ethylene glycol diacrylate, triethylene glycol triacrylate,
1,3-butanediol diacrylate, tetramethylene glycol diacrylate,
propylene glycol diacrylate, trimethylolpropane triacrylate,
trimethylolethane triacrylate, tetraethylene glycol diacrylate,
pentaerithritol diacrylate, pentaerithritol triacrylate,
pentaerithritol tetraacrylate, dipentaerithritol diacrylate,
dipentaerithritol triacrylate, dipentaerithritol tetraacrylate
dipentaerithritol pentaacrylate, dipentaerithritol hexaacrylate,
tripentaerithritol octaacrylate, sorbitol triacrylate, sorbitol
tetraacrylate, sorbitol pentaacrylate, sorbitol hexaacrylate and
polyester acrylate oligomer; methacrylic esters such as
tetramethylene glycol dimethacrylate, triethylene glycol
dimethacrylate, trimethylolpropane trimethacrylate,
trimethylolethane trimethacrylate, pentaerithritol dimethacrylate,
pentaerithritol trimethacrylate, dipentaerithritol dimethacrylate,
dipentaerithritol tetramethacrylate, tripentaerithritol
octamethacrylate, ethylene glycol dimethacrylate, 1,3-butanediol
dimethacrylate, tetramethylene glycol dimethacrylate and sorbitol
tetramethacrylate; itaconic esters such as ethylene glycol
diitaconate, propylene glycol diitaconate, 1,3-butanediol
diitaconate, 1,4-butanediol diitaconate, tetramethylene glycol
diitaconate, pentaerithritol diitaconate, dipentaerithritol
triitaconate, dipentaerithritol pentaitaconate, dipentaerithritol
hexaitaconate and sorbitol tetraitaconate; crotonic esters such as
ethylene glycol dicrotonate, propylene glycol dicrotonate,
tetramethylene glycol dicrotonate, pentaerithritol dicrotonate and
sorbitol tetracrotonate; isocrotonic esters such as ethylene glycol
diisocrotonate, pentaerithritol diisocrotonate and sorbitol
tetraisocrotonate; maleic esters such as ethylene glycol dimaleate,
triethylene glycol dimaleate, pentaerithritol dimaleate and
sorbitol tetramaleate; and a mixture of some of these esters.
Examples of the oligoesters may include oligoester acrylate and
oligoester methacrylate (hereinafter referred to merely as
oligoester (metha)acrylate, thereby representing both or either one
of these).
The oligoester (metha)acrylate is a reaction product obtained by
esterification reaction of acrylic or methacrylic acid and a
polycarboxylic acid with a polyol, and is assumed to have a
chemical structure of the formula: ##STR2## (wherein, R represents
a hydrogen atom or a methyl group, Q represents a residue having at
least one ester bond and being formed by condensation of the polyol
and the polycarboxylic acid, and p is an integer of 1 to 6).
Example of the polyol giving the residue represented by Q may
include polyols such as ethylene glycol, 1,2-propylene glycol,
1,4-butanediol, 1,6-hexanediol, trimethylolpropane,
trimethylolethane, 1,2,6-hexanetriol, glycerol, pentaerithritol and
sorbitol; polyether type polyols such as diethylene glycol,
triethylene glycol, tetraethylene glycol, decaethylene glycol,
polyethylene glycol, dipropylene glycol, tripropylene glycol,
tetrapropylene glycol and polypropylene glycol, etc.
Examples of the polycarboxylic acid giving the residue represented
by Q may include aromatic polycarboxylic acids such as phthalic
acid, isophthalic acid, terephthalic acid, tetrachlorophthalic
acid, tetrabromophthalic acid, trimellitic acid, pyromellitic acid,
benzophenone dicarboxylic acid and resorcinol diacetic acid;
unsaturated aliphtic polycarboxylic acids such as maleic acid,
fumaric acid, Himic Acid (trademark, produced by Hitachi Chemical
Co., Ltd.) and itaconic acid; saturated aliphatic polycarboxylic
acid such as malonic acid succinic acid, glutaric acid, adipic
acid, pimelic acid, sebacic acid, dodecanoic acid and
tetrahydrophthalic acid, etc.
As the acid anhydride which may be used in the invention, there may
include phthalic anhydride, tetrahydrophthalic anhydride,
methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride,
methylhexahydrophthalic anhydride, maleic anhydride, trimellitic
anhydride and hexachloroendomethylenetetrahydrophthalic
anhydride.
As the imide compound which may be used in this invention, a
maleimide represented by the following general formula: ##STR3##
(wherein X represents a divalent hydrocarbon group such as an
alkylene group, a cycloalkylene group, a monocyclic or polycyclic
arylene group or the like, or a divalent hydrocarbon group being
combined with a divalent group such as --CH.sub.2 --, --CO--,
--SO.sub.2 --, --CONH-- or the like), is preferable. Examples of
the maleimide compound may include N,N'-phenylenebismaleimide,
N,N'-hexamethylenebismaleimide,
N,N'-methylene-di-p-phenylenebismaleimide,
N,N'-oxy-di-p-phenylenebismaleimide,
N,N'-4,4'-benzophenonebismaleimide,
N,N'-(3,3'-dimethylene-di-p-phenylenebismaleimide,
N,N'-methatoluilenebismaleimide and the like.
Each of the acid anhydrides and the phenol series compounds may be
mixed in the range of not more than 1 in terms of weight ratio
based on the epoxy compound, respectively.
The aluminum compound to be used in this invention may be either
inorganic aluminum compounds or organic aluminum compounds, but is
preferably compounds having an organic group selected from the
group consisting of an alkoxy group, a phenoxy group, an acyloxy
group, a .beta.-diketonato group, an o-carbonylphenolato group,
etc.
Of the above organic groups, examples of the alkoxy group may
include a methoxy group, an ethoxy group, an isopropoxy group, a
butoxy group, a pentoxy group, etc.; examples of the phenoxy group
may include a phenoxy group, an o-methylphenoxy group, an
o-methoxyphenoxy group, a p-nitrophenoxy group, a
2,6-dimethylphenoxy group, etc.; examples of the acyloxy group may
include an acetato group, a propionato group, an isopropionato
group, a butylato group, a stearato group, an ethylacetoacetato
group, a propylacetoacetato group, an isopropylacetoacetato group,
an n-butylacetoacetato group, a sec-butylacetoacetato group, a
diethylmalonato group, a dipivalaloylmethanato group, etc.;
examples of the .beta.-diketoanto group may include an
acetylacetonato group, a trifluoroacetylacetonato group, a
hexafluoroacetylacetonato group, ##STR4## and examples of the
o-carbonylphenolato group may include a salicylaldehydato group,
etc.
More specifically, examples of the aluminum compounds mentioned
above may include trismethoxyaluminum, trisethoxyaluminum,
trisisopropoxyaluminum, trisphenoxyaluminum,
trisparamethylphenoxyaluminum, isopropoxydiethoxyaluminum,
trisbutoxyaluminum, trisacetoxyaluminum, trisstearatoaluminum,
trisbutyratoaluminum, trispropionatoaluminum,
trisisopropionatoaluminum, trisacetylacetonatoaluminum,
tris(trifluoroacetylacetonato)aluminum,
tris(hexafluoroacetylacetonato)aluminum,
trisethylacetoacetatoaluminum, trissalicylaldehydatoaluminum,
tris(diethylmalonato)aluminum, trispropylacetoacetatoaluminum,
trisbutylacetoacetatoaluminum, tris(dipivaloylmethanato)aluminum,
diacetylacetonatodipivaloylmethanatoaluminum, ##STR5##
These aluminum compounds may be used independently or in admixture
with one another. They are generally used in an amount of 0.001 to
10% by weight, preferably 0.05 to 5% by weight based on the epoxy
resins. An amount of the aluminum compounds below 0.001% by weight
cannot give sufficient curing characteristics, on the other hand,
an amount thereof in excess of 10% by weight would make cost of the
compositions expensive and cause the electric characteristics to
deteriorate.
The silicon compound having a peroxysilyl group to be used in this
invention is represented by the following formula:
(wherein R.sup.1 represents a hydrogen atom, a halogen atom, an
alkyl group having from 1 to 5 carbon atoms, a vinyl group, an
alkoxy group having from 1 to 5 carbon atoms or a substituted or
unsubstituted aryl group; R.sup.2 represents a hydrogen atom, an
alkyl group having from 1 to 10 carbon atoms or a substituted or
unsubstituted aryl group and n is an integer of 0 to 3).
In the above formula, examples of the alkyl group of R.sup.1 having
1 to 5 carbon atoms may include a methyl group, an ethyl group, an
isopropyl group, a n-propyl group, a n-butyl group, a tert-butyl
group, a sec-butyl group, a n-pentyl group, etc.; examples of the
alkoxy group having 1 to 5 carbon atoms may include a methoxy
group, an ethoxy group, an isopropoxy group, a n-butoxy group, an
n-pentyloxy group, etc.; examples of the aryl group may include a
phenyl group, a naphthyl group, an anthranyl group, a benzyl group,
an .alpha.,.alpha.'-dimethylbenzyl group, a
1,2,3,4-tetrahydro-1-naphthyl group, etc; and examples of the alkyl
group of R.sup.2 having 1 to 10 carbon atoms may include a methyl
group, an ethyl group, an isopropyl group, an n-propyl group, a
n-butyl group, a tert-butyl group, a sec-butyl group, a n-pentyl
group, a hexyl group, a heptyl group, an octyl group, a nonyl
group, a decyl group, etc. The alkyl group having 1 to 5 carbon
atoms and the aryl group may have a substituents such as a halogen
atom, a haloalkyl group, a nitro group, a cyano group, a methoxy
group or the like.
Examples of the silicon compounds having the peroxysilyl group may
include compounds of the following formulas: ##STR6##
These silicon compounds are preferably used in an amount of 0.1 to
20% by weight, more preferably 1 to 10% by weight, based on the
epoxy resin. An amount of the silicon compound below 0.1% by weight
cannot give sufficient curing characteristics, on the contrary an
amount thereof in excess of 20% by weight can also be used, but
would make the compositions expensive and would present a problem
concerning decomposition products of the catalyst components.
As the photosensitizer used in this invention, there may be
employed any of those which are capable of photosensitizing the
foregoing compounds, and which are selected depending on the kinds
of the epoxy resins, light source, etc.
Examples of the above photosensitizers may include aromatic
hydrocarbons, benzophenone and derivatives thereof, esters of
o-benzoylbenzoic acids, acetophenone and derivatives thereof,
benzoin and benzoin ethers and derivatives thereof, xanthone and
derivatives thereof, thioxanthone and derivatives thereof,
disulfide compounds, quinone compounds, halogenated hydrocarbons,
amines, etc.
Examples of the aromatic hydrocarbon may include benzene,
benzene-d.sub.6, toluene, p-xylene, fluorobenzene, chlorobenzene,
bromobenzene, iodobenzene, naphthalene, 1-methylnaphthalene,
2-methylnaphthalene, 1-fluoronaphthalene, 1-chloronaphthalene,
2-chloronaphthalene, 1-bromonaphthalene, 2-bromonaphthalene,
1-iodonaphthalene, 2-iodonaphthalene, 1-naphthol, 2-naphthol,
biphenyl, fluorene, p-terphenyl, acenaphthene, p-quaterphenyl,
triphenylene, phenanthrene, azulene, fluoranthene, chrycene,
pyrene, 1,2-benzpyrene, anthracene, 1,2-benzanthracene,
9,10-dichloroanthracene, 9,10-dibromoanthracene,
9,10-diphenylanthracene, perylene, tetracene, pentacene, etc.
Examples of the benzophenone and the derivatives thereof may
include benzophenone, 2,4-dimethylbenzophenone,
2,4-dichlorobenzophenone, 4,4'-bis(dimethylamino)benzophenone,
etc.
Examples of the esters o-benzoylbenzoic acids may include methyl
o-benzoylbenzoate, ethyl o-benzoylbenzoate, phenyl
o-benzoylbenzoate, ##STR7##
Examples of the acetophenone and the derivatives thereof may
include acetophenone, 4-methylacetophenone, 3-methylacetophenone,
3-methoxyacetophenone, etc.
Examples of the benzoin, the benzoin ethers and the derivatives of
these may include benzoin, benzoin methyl ether, benzoin ethyl
ether, benzoin isopropyl ether, benzoin n-butyl ether, benzoin
triphenylsilyl ether, ##STR8##
Examples of the xanthone and the derivatives thereof may include
xanthone, 2,4-dimethylxanthone, 2,4-dichloroxanthone, etc.
Examples of the thioxanthone and the derivatives thereof may
include thioxanthone, 2,4-dimethylthioxanthone,
2,4-dichlorothioxane, etc.
Examples of the disulfide compounds may include; ##STR9##
Examples of the quinone series compounds may include benzoquinone,
naphthoquinone, anthraquinone, 5,12-naphthacene dione, 2,7-pyrene
dione, etc.
Examples of the halogenated hydrocarbons may include carbon
tetrachloride, hexachloroethane, carbon tetrabromide, ##STR10##
Examples of the amines may include diphenylamine, carbazole,
triphenylamine, ##STR11##
Examples of the other photosensitizers may include propiophenone,
anthrone, benzaldehyde, butylophenone, 2-naphthylphenylketone,
2-naphthaldehyde, 2-acetonaphthone, 1-naphthylphenylketone,
1-acetonaphthone, 1-naphtholaldehyde, fluorenone,
1-phenyl-1,2-propane dione, benzoethrile, acetone, biacetyl,
acridine orange, acridine, Rhodamine-B, eosine, fluorescein,
##STR12##
The photosensitizers exemplified in the above may be used alone or
in combination, and should be mixed preferably in an amount of from
0.001 to 10% by weight, more preferably 0.01 to 5% by weight, based
on the epoxy resin.
The photo-curable compositions of the present invention can be
cured by methods such as room-temperature photo-curing,
high-temperature photo-curing, after-cure which is effected after
the photo-curing, etc. The wavelength of light necessary for the
photo-curing will generally be from 180 nm to 700 nm, preferably
from 250 nm to 500 nm; the irradiation time will generally be from
10 sec. to 180 min., preferably from 30 sec. to 30 min., depending
on the epoxy resin composition and the catalyst to be used; and the
temperature in case of high-temperature photo-curing will generally
be from 20.degree. C. to 200.degree. C., preferably from 60.degree.
C. to 120.degree. C., depending on the epoxy resin composition and
the catalyst to be used. Examples of the light source to be used in
this invention may include a high-pressure mercury-vapor lamp, a
carbon arc lamp, a xenon lamp, an argon glow discharge tube and the
like. In case of after-cure which is effected after the
photo-curing will generally be carried out at 50.degree. C. to
200.degree. C., preferably at 100.degree. C. to 180.degree. C., and
effected for 1 to 10 hrs., preferably for 2 to 5 hrs., depending on
the epoxy resin composition and the catalyst to be used.
This invention will be described in greater detail by giving the
following Examples.
EXAMPLE 1
10 g of ERL 4221 (trade name, available from UCC Co. Ltd.; an
alicyclic epoxy resin having following formula [1]), 0.3 g of
tris(propylacetoacetato)aluminum, 0.5 g of
t-butylperoxytriphenylsilane and 0.1 g of benzophenone were mixed
and homogeneously dissolved.
The thus obtained photo-curable epoxy resin series composition was
applied onto an aluminum plate and exposed to light emitted from a
high-pressure mercury-vapor lamp (80 W/cm) (available from Tokyo
Shibaura Denki K.K.) at a distance from 15 cm, the composition was
cured within 1 minute.
On the other hand, the same composition mentioned above except that
benzophenone was not added was prepared and exposed to light in the
same conditions as mentioned above, the cured product was not
obtained within 1 minute. ##STR13##
EXAMPLE 2
10 g of ERL 4206 (trade name, available from UCC Co. Ltd.; an epoxy
compound having following formula [2], epoxy equivalent; 70,
molecular weight: 139), 4 g of Epikote 828 (trade name, available
from Shell Kagaku K.K., Japan; bisphenol A type epoxy resin, epoxy
equivalent: 190-210, molecular weight: 380), 0.5 g of
tris(ethylacetoacetato)aluminum, 0.5 g of
di(t-butylperoxy)diphenylsilane and 0.1 g of benzoin ethyl ether
were mixed and homogenously dissolved.
The thus obtained photo-curable epoxy resin series composition was
applied onto an aluminum plate and exposed to light for 1 minute in
the same manner as in Example 1, the reaction system had already
been gelled.
On the other hand, when the same composition mentioned above,
except that benzoin ethyl ether was not added, was prepared and
exposed to light in the same conditions as mentioned above, only a
soft gellated prodect has been formed after a one minute exposure.
##STR14##
EXAMPLE 3
100 g of ERL 4221, 30 g of Epikote 154 (trade name, available from
Shell Kagaku K.K., Japan; phenol novolac type epoxy resin, epoxy
equivalent: 172-180), 10 g of Epikote 828, 0.3 g of
tris(salicylaldehydato)aluminum, 4 g of
t-butylperoxytriphenylsilane and 0.5 g of thioxanthone were mixed
and homogeneously dissolved.
The thus obtained photo-curable epoxy resin series composition was
applied onto an aluminum plate. When exposed to an ultra-violet ray
emitted from a mercury lamp (80 W/cm) for 1 minute, there was
yielded a satisfactory cured resin plate. Measurement of the
electric characteristics of the cured resin plate indicated that a
dielectric loss tangent value (tan .delta.) thereof was 2.0% at
100.degree. C.
The cured resin plate was then after-cured at 130.degree. C. for 5
hours and the tan .delta. value thereof was measured again to be
4.5% at 180.degree. C.
EXAMPLE 4
60 g of ERL 4221, 20 g of Epikote 152 (Trade Name, available from
Shell Kagaku K.K., Japan; phenol novolac type epoxy resin, epoxy
equivalent: 172-179), 2 g of tris(saliycilaldehydato)aluminum, 4 g
of t-butylperoxytriphenylsilane and 0.5 g of benzil were mixed and
homogeneously dissolved.
The thus obtained photo-curable epoxy resin series composition was
applied onto an aluminum plate. When exposed to a light for 1
minute in the same manner as in Example 3, there was yielded a
satisfactory cured resin plate.
Measurement of the characteristics of the cured resin plate
indicated that a dielectric loss tangent value (tan .delta.) and a
volume resistivity thereof were 3.7% and 2.5.times.10.sup.13
.OMEGA.m, respectively, at 100.degree. C.
The cured resin plate was then after-cured at 130.degree. C. for 5
hours and the tan .delta. value thereof was measured again to be
4.5% at 180.degree. C.
COMPARATIVE EXAMPLE 1
100 g of ERL 4221, 30 g of epikote 828 and 0.3 g of
diphenyliodoniumtetrafluoroborate were mixed and homogeneously
dissolved.
The thus obtained photo-curable epoxy resin series composition was
applied onto an aluminum plate and exposed to light for 1 minute in
the same manner as in Example 3.
When an attempt was made to after-cure the resin plate and measure
the tan .delta. value thereof, sufficient curing could not be
obtained to permit the tan .delta. measurement, in contrast to the
above-mentioned examples.
As will be seen from the obtained results, the composition of the
present invention quickly harden when exposed to light and it is
confirmed tht the electric insulating characteristics of the
obtained cured product are extremely excellent.
EXAMPLES 5 TO 19
Fifteen kinds of photo-curable epoxy resin type compositions each
having the composition as shown in Table 1 were prepared.
As shown in Table 1, employed as epoxy resin were ERL 4221 (trade
name, available from UCC Co. Ltd.; the alicyclic epoxy resin), ERL
4206 (trade name, available from ditto), ERL 4234 (trade name,
available from ditto, an alicyclic epoxy resin having following
formula [3], epoxy equivalent: about 140), Epikote 828 (trade name,
available from Shell Kagaku K.K., Japan; bisphenol A type epoxy
resin, epoxy equivalent: 190-210, molecular weight: 380), Epikote
1001 (trade name, available from ditto, epoxy equivalent: 450 to
525, molecular weight: 900) and Epikote 1004 (trade name, available
from ditto, epoxy equivalent: 900 to 1000, molecular weight: about
1400).
As phenol series compounds, employed were bisphenol A and
catechol.
As ethylenic compounds, employed were (1) trimethylolpropane
triacrylate and (2) pentaerythrytol dimethacrylate.
As acid anhydrides, employed were (3) epichlone B-570 (trade name,
available from Dainippon Ink and Chemicals, Inc.,
methyl-.DELTA..sup.4 -tetrahydrophthalic anhydride) and (4) Likacid
MH-700 (trade name, available from Shin-nippon Rika Co., Ltd.,
methylhexahydrophthalic anhydride). As imide compounds, employed
were (5) N,N'-phenylenebismaleimide and (6)
N,N'-4,4'-benzophenonebismaleimide.
Further, as aluminum compounds, employed were;
(i) trisacetylacetonatoaluminum,
(ii) tris(ethylacetoacetato)aluminum,
(iii) tris(n-butylacetylacetato)aluminum, and
(iv) trissalicylaldehydatoaluminum.
Moreover, as silicon compounds, employed were;
(a) triphenyl(t-butylperoxy)silane,
(b) triphenyl(.alpha.,.alpha.'-dimethylbenzylperoxy)silane,
(c) vinyldiphenyl(tert-butylperoxy)silane, and
(d) diphenyl(.alpha.,.alpha.'-dimethylbenzylperoxy)silane.
As sensitizers, employed were (A) naphthacene, (B) benzophenone,
(C) benzoin isopropyl ether and (D) 2,4-dimethylthioxantone.
By the use of the above, the photo-curable epoxy resin type
compositions were each applied onto an aluminum plate, and as to
the compositions of Examples 5 to 13, they were subjected to
ultraviolet cure by passing them at a speed of 1 m/min. through a
curing box having a length of 2 m which was provided three sets of
high-pressure mercury lamps H2000L/81N (available from Tokyo
Shibaura Denki K.K.) of 2 KW each. As to the compositions of
Examples 14 to 19, after they were subjected to the same treatment
as mentioned above, they were treated a post-curing at 150.degree.
C. for 2 hours. The thus obtained each cured product was measured a
tan .delta. value thereof. The obtained results are also shown in
Table 1. ##STR15##
TABLE 1
__________________________________________________________________________
Components Example No. et al. 5 6 7 8 9 10 11 12 13 14 15 16 17 18
19
__________________________________________________________________________
Epoxy reins: ERL 4221 60 60 50 50 50 40 60 60 40 10 10 10 10 -- --
ERL 4206 -- -- 10 -- -- 10 -- -- -- -- -- 10 -- -- -- ERL 4234 --
-- -- 10 -- -- -- -- -- -- -- -- -- -- -- Epikote 828 20 -- -- 10
10 -- 20 -- -- 60 60 60 60 50 60 Epikote 1001 -- 20 -- -- -- 10 --
20 -- 30 -- -- -- -- -- Epikote 1004 -- -- 20 10 -- -- -- -- 10 --
30 -- 20 -- -- Bisphenol A 20 -- -- -- -- -- -- -- -- 20 -- -- --
-- -- Catechol -- 20 -- 10 -- -- -- -- 5 -- -- -- -- 10 --
Ethylenic -- -- 20 -- -- -- -- -- -- -- 20 -- -- -- -- compound (1)
Ethylenic -- -- -- 20 -- -- -- -- 5 -- -- -- -- 10 -- compound (2)
Acid -- -- -- -- 40 -- -- -- -- -- -- 20 -- -- 30 anhydride (3)
Acid -- -- -- -- -- 40 -- -- 30 -- -- -- -- 20 -- anhydride (4)
Imide -- -- -- -- -- -- 20 -- 10 -- -- -- 10 10 -- compound (5)
Imide -- -- -- -- -- -- -- 20 -- -- -- -- -- -- 10 compound (6)
Aluminum compounds: (i) 2 -- -- -- -- -- -- -- -- -- -- -- -- -- --
(ii) -- 2
-- -- -- -- 2 -- -- -- 2 -- -- -- -- (iii) -- -- 2 -- -- 2 -- 2 --
2 -- 2 -- -- 2 (iv) -- -- -- 2 2 -- -- -- 2 -- -- -- 2 2 -- Silicon
compounds: (a) 2 -- -- -- -- -- 2 -- -- 2 -- -- -- -- -- (b) -- 2
-- -- 2 -- -- -- -- -- -- -- 2 2 -- (c) -- -- 2 -- -- 2 -- -- -- --
-- 2 -- -- 2 (d) -- -- -- 2 -- -- -- 2 2 -- 2 -- -- -- --
Photo-sensitizer: (A) 0.2 -- -- -- -- -- -- -- -- -- -- -- 0.1 --
-- (B) -- 0.2 -- -- -- 0.2 -- -- -- 0.1 -- -- -- 0.1 -- (C) -- --
0.2 -- 0.2 -- 0.2 -- 0.2 -- 0.1 -- -- -- 0.1 (D) -- -- -- 0.2 -- --
-- 0.2 -- -- -- 0.1 -- -- -- tan.delta. (%) 150.degree. C. 1.8 1.2
1.5 1.1 1.4 1.7 1.6 1.5 1.8 2.3 3.2 2.5 2.9 1.3 2.2 180.degree. C.
2.7 2.1 2.4 2.0 2.5 2.8 2.9 3.1 3.0 4.1 4.3 3.7 4.3 2.1 3.9
__________________________________________________________________________
As is clear from the above results, the compositions of the present
invention quickly harden when exposed to light and give cured
products which show extremely excellent electric insulating
characteristics.
The photo-curable epoxy resin type compositions of the present
invention harden in short time when exposed to light due to the use
of an aluminum compound and a silicon compound having a peroxysilyl
group as catalyst components. Moreover, the obtained cured product
is extremely excellent in the electric characteristics such as a
tan .delta. value since it contains no ionic impurities, and
thereby does not cause the corrosion of an electric appliance when
the product is used in the electric appliance. Therefore, the cured
product can be used for wide variations of applications such as
resist materials and insulating materials for electric appliances,
particularly for coils. It should thus be concluded that the
industrial value of the photo-curable epoxy resin is extremely
great.
* * * * *